JPH053852A - Curved tube for endoscope - Google Patents

Abstract

PURPOSE:To constitute a wire receiver in the curved tube for an endoscope so that its operating wire insert-through part is not shifted to the inside peripheral surface side of a nodal ring, and also, it can be fixed, while obtaining necessary strength. CONSTITUTION:A wire receiver 21 is formed from leg parts 22a, 22b and an operating wire insert-through part 23. Also, thickness t1 to the leg parts 22a, 22b is formed larger than thickness t2 of the operating wire insert-through part 23. Moreover, the leg parts 22a, 22b of the wire receiver 21 are deposited and fixed with a laser light to a fixed position on the inside peripheral surface of a nodal ring 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending tube installed in a bending portion of a flexible endoscope.

[0002]

2. Description of the Related Art As shown in FIG. 18, a flexible endoscope 1 generally comprises an operating section 2 and an insertion section 3. The insertion portion 3 includes a flexible tube portion 4 that is continuously provided to the operation portion 2, a bending portion 5 that is continuously provided to the flexible tube portion 4, and a tip forming portion that is continuously provided at a tip end side of the bending portion 5. It is composed of 6.

Further, an eyepiece for observing the inside of a body cavity through an operation knob 7 for bending the bending portion 5 as will be described later, and an observation window 8 formed in the tip forming portion 6 on the operation portion 2. A unit 9, a universal cord 10 connected to a light source device (not shown), and an operation button 11 for supplying air and liquid are provided.

A bending tube 12 is installed in the bending portion 5, and the bending tube 12 is constructed by connecting a plurality of node rings 13 so as to be rotatable relative to each other, as shown in FIG.

That is, the node ring 13 is composed of a cylindrical short tube portion 14, and a pair of connecting portions 15 are respectively deviated by 180 degrees in the circumferential direction on both end surfaces of the short tube portion 14 and deviated by 90 degrees on both end surfaces. The connecting portions 15 corresponding to the adjacent joint rings 13 of the respective joint rings 13 are rotatably connected to each other by rivets 16 so that the joint pipes 15 are protruded along the axial direction of the short pipe portion 14 at different positions. There is.

On the inner peripheral wall surface of one end face of each node ring 13, a groove portion 19 for supporting the cylindrical wire receiver 17 is formed at a position offset by 90 degrees from the extending position of the connecting portion 15 along the circumference. Two locations are provided at equal positions, that is, at positions shifted from each other by 180 degrees.

A groove portion 19 similar to the inner peripheral wall surface of the one end face is also provided on the inner peripheral wall surface of the other end face of each node ring 13. That is, the groove portion 19 of the inner peripheral wall of the other end surface is provided at two positions with the inner periphery equally spaced from the groove portion 19 of the inner peripheral wall surface of the one end surface by 90 degrees.

The above-mentioned four groove portions 19 may be provided by laser cutting or press cutting.
A cylindrical wire receiver 17 for inserting and supporting the operation wire 18 is welded to the outer peripheral surface of the node ring 13 by irradiation with a laser or the like. Therefore, four wire receivers 17 are welded to the inner peripheral wall surface of each node ring 13. (Details of the method for welding the wire receiver 17 will be described later.)

The operation wires 18 are inserted through the operation wire insertion portions 20 of the wire receivers 17 of the respective node rings 13 located at corresponding positions in the circumferential direction.
One end of each of these operation wires 18 is fixed to the node ring 13 located at the most distal end (not shown), and the other end side is guided to the operation part 2 where it is displaced 180 degrees in the circumferential direction of the node ring 13. The pair of operation wires 18 are coupled to the operation knob 7 so as to interlock with each other. That is, with respect to each pair of operation wires 18 which are displaced by 180 degrees, when one is pulled, the other is pushed. Therefore, the curved portion 5
The bending tube 12 constituting the
It is configured to be bendable in the vertical and horizontal directions via the operation wire 18 of the book.

Now, the bending tube 1 of the endoscope 1 having the above structure.
As a method of welding the wire receiver 17 to the second node ring 13, the following technique is known.

As shown in FIG. 20, a groove portion 19 having a length 1 shorter than the length L of the wire receiver 17 is provided in the node ring 13.
A part of the cylindrical wire receiver 17 is ground according to the shape (curvature) of the inner peripheral surface of the node ring 13, and the wire receiver 17 is cut.
The scraped surface of the node ring 13 is matched with the groove portion 19 from the inner peripheral surface side, and the groove portion 19 and the wire receiver 1 are arranged from the outer peripheral surface side of the node ring 13.
The wire receiver 17 is welded by irradiating the boundary with the scraped surface of 7 with a laser or the like.

Further, as shown in FIG. 21, a groove portion 19 having a length l longer than the length L of the wire receiver 17 is provided in the node ring 13, and the cylindrical wire receiver 17 is provided on the inner peripheral surface side of the node ring 13. From the outer peripheral surface side of the node ring 13 by irradiating the boundary between the groove portion 19 and the wire receiver 17 with a laser or the like to weld the wire receiver 17 or as shown in FIG.
The groove portion 19 of the node ring 13 of 0 is deformed into a shape in which a plurality of holes 19a are arranged in the longitudinal direction, and the residual portion of the node ring 13 located between each hole 19a and the hole 19a is melted by a laser or the like. A welding method has been carried out in which the welding area is increased so as to flow between the node ring 13 and the wire receiver 17 and the welding strength is improved.

The welding methods shown in FIGS. 20 to 22 are shown in the first to third embodiments of the invention described in JP-A-63-225060.

[0014]

In general steel materials, when heated above the melting point, the crystal grains become coarse and become brittle. That is,
The heated part becomes brittle and its strength decreases.

When a laser beam or the like is irradiated, the melting point becomes higher than the melting point, the above phenomenon occurs, and the strength decreases. Also,
Since irradiation with a laser or the like is a local and instantaneous heat input, residual stress is likely to occur at the boundary between the melted portion and the unmelted portion, and the strength tends to further decrease at the boundary portion.

Based on the above phenomenon, problems of the prior art will be described. FIG. 23 is a cross-sectional view after laser irradiation according to a conventional technique (FIG. 21) in which a groove is provided in the node ring 13 and a wire receiver 17 is attached to the groove.

As can be seen from the figure, the melting portion 70 by the laser or the like shown by the shaded portion extends to the wire receiver 17. As described above, the strength tends to decrease at the boundary between the melted portion and the unmelted portion, and in addition, since the wall thickness of the wire receiver 17 is thinner than that of the node ring 13, the melted portion 70 of the wire receiver 17 is The boundary 72 with the unmelted portion 71 is apt to be broken, so that the required strength cannot be satisfied.

In order to obtain the required strength, the wire receiver 17
It is possible to increase the wall thickness of the
Since the operation wire 18 is inserted therein, the inner diameter cannot be reduced. In addition, the fiber inside the node ring 13,
There is a limit to increase the outer diameter of the wire receiver 17 because an air / liquid feeding channel, a forceps insertion channel, etc. (not shown) are inserted, and the wall thickness of the wire receiver 17 must be increased to satisfy the required strength. I couldn't increase it.

Similarly, in another wire receiving and welding method (FIGS. 20 and 22) shown in the above-mentioned prior art, as shown in FIGS.
A portion 71 where 0 is formed and is not melted with the melting portion 70.
The boundary 72 between and is easily broken, and the required strength cannot be satisfied.

Further, the welding method shown in FIGS. 20 to 22 has the following problems. That is, since the groove portion 19 is provided in the node ring 13 or the cylindrical wire receiver 17 is ground to match the shape of the inner peripheral surface of the node ring 13, the operation wire insertion portion 20 of the wire receiver 17 is formed as shown in FIG. It shifts to the inner peripheral surface side of the node ring 13. That is, the normal welding position indicated by the dotted line is displaced to the welding position indicated by the solid line. (The welding method shown in FIG. 21 is shown.) Therefore, when the operation wire 18 is attached after the insertion position of the operation wire 18 is displaced to the inner peripheral surface side of the node ring 13 and the node ring 13 is connected with the rivet 16. , The operation wire 18 hits the rivet 16,
The insertability of the operation wire 18 deteriorates, and the operation wire 1
Inserting 8 takes time. Further, after the operation wire 18 is attached, the portion of the operation wire 18 that contacts the rivet 16 is bent, and the operation wire 18 does not move smoothly. Therefore, the rotatability of each node ring 13 deteriorates. In addition, there is a drawback that the portion of the operation wire 18 that contacts the rivet 16 is rubbed and the portion is broken.

The present invention has been made in view of the above problems, and eliminates the above drawbacks, that is, the operation wire insertion portion 20 of the wire receiver 17 is not displaced to the inner peripheral surface side of the node ring 13, and An object of the present invention is to provide a bending tube for an endoscope that can obtain required strength.

[0022]

Means and Actions for Solving the Problems The fact that the boundary between the melted portion and the non-melted portion such as the laser described in the problem to be solved by the invention is lowered means that the boundary is present. This means that a part will break with a smaller stress than other parts. In order to prevent fracture at the boundary, it is necessary to make the stress applied to this boundary smaller than the stress applied to other parts.

The present invention relates to a bending tube in which a wire receiver is fixed to an inner surface of a node ring installed in a bending portion of an endoscope,
When the wire receiver and the node ring are integrally welded together by a laser or the like, the cross-sectional area where the boundary between the molten portion generated in the wire receiver and the unmelted portion is located is the operation wire insertion portion of the wire receiver. A wire receiver having a shape larger than the cross-sectional area of the wire is used, and the wire receiver is provided with the operation wire insertion portion at a position where the operation wire does not hit the rivet connecting the node rings.

By the above-mentioned means, heat is not generated in the operation wire insertion portion of the thin wire receiver, the wire receiver can always be fixed in the normal position, and the wire receiver and the node ring are welded. The strength is significantly improved. Therefore, the operation wire will not hit the rivet that connects the node rings, and the insertability of the operation wire,
The rotatability of each node ring is significantly improved.

[0025]

Embodiments of the bending tube for an endoscope of the present invention will be described with reference to the drawings. 20 to 26 in the above-mentioned related art.
In each of the embodiments, the same members and the same components are designated by the same reference numerals, and the description thereof will be omitted.

[0026]

Embodiment 1 FIGS. 1 to 5 show Embodiment 1 of a bending tube for an endoscope according to the present invention. FIG. 1 is a perspective view of a node ring having four wire receivers attached, and FIG. 2 is a perspective view of the wire receiver. 3 and 4 are enlarged cross-sectional views of the part to which the wire receiver is attached.
FIG. 3 is an explanatory diagram of a laser light irradiation method.

As shown in FIG. 1, the node ring 13 is formed of a simple circular tube without forming a shape such as a recess, a groove or a hole at the joint with the wire receiver 21. As shown in FIG. 2, the wire receiver 21 is formed of long plate-shaped foot portions 22a and 22b facing each other with a gap between the lengthwise directions, and a cylindrical operation wire insertion portion 23 connecting the both foot portions. There is. Feet 22a, 22 of the wire receiver 21
The joint portions 22c, 22d between the b and the node ring 13 have a surface shape corresponding to the inner peripheral surface of the node ring 13, and the foot portions 22a, 22
The thickness t _{1 of} 2b is formed to be larger than the thickness t ₂ of the operation wire insertion portion 23.

Generally, the outer diameter of the node ring 13 used for a bending tube for an endoscope is φ5 mm to φ15 mm, and the wall thickness is 0.2 mm to 0.4.
mm, the thickness of the operation wire insertion part 23 of the wire receiver 21 is 0.2 mm to 0.3 mm, and the size d of the inner peripheral surface of the insertion part 23 is φ0.5 mm to 0.7 mm. Here, outer diameter φ8m
A node ring 13 with a wall thickness of 0.3 mm and a diameter of 0.3 mm is taken as a representative part. Wire receiver 2 connected to node ring 13 of the above size
As 1, foot 22a, the thickness of 22b t _1: 0.35 mm, height k of the foot 22: 0.2 mm, length of the wire receiver 21 L:
A component having a size of 1.5 mm, a thickness t _{2 of} the operation wire insertion part 23: 0.2 mm, and a size d of the inner peripheral surface of the operation wire insertion part 23: φ 0.7 mm is used. As shown in FIG. 3, node ring 1
The foot portions 22a and 22b of the wire receiver 21 are closely adhered to the inner peripheral surface of 3, and a laser beam or an energy beam such as an electron beam is applied from the outer peripheral surface side of the node ring 13 along the length direction of the foot portions 22a and 22b. Irradiation is performed to fix the legs 22a and 22b of the wire receiver 21 to the inner peripheral surface of the node ring 13 by welding. For example, when YAG laser light is used as the energy beam, the output is 4 to 5 J, the pulse width is 10 msec, the focal length of the condenser lens is f = 100 mm, the defocus amount is +4 mm, and the diameter of the incident beam to the condenser lens is 4.8 mm. At 0.4mm ~
Penetration depth q of 0.45 mm, surface diameter of penetration part p0.5
5 to 0.6 mm can be obtained. By irradiating the outer peripheral surface of the node ring 13 with the laser light under the above conditions, the molten portion 70 generated in the wire receiver 21 and the unmelted portion 71
Since the boundary 72 with and is formed by the foot portions 22a and 22b having a larger cross-sectional area than the operation wire insertion portion 23, when a force is applied to the wire receiver 21 by the bending operation of the bending tube for an endoscope, The stress at the boundary 72 is smaller than the stress at the operation wire insertion portion 23. Therefore, it is possible to prevent the boundary 72 from being broken, and the strength is significantly improved.

As shown in FIG. 4, the method of irradiating the node ring 13 and the wire receiver 21 with the laser light is as shown in FIG. 4, in which the foot 22a, 22b of the wire receiver 21 is substantially centered with the node ring 13. Is welded and fixed by a laser spot, or, as shown in FIG. 5, the foot portions 22a and 22b of the wire receiver 21 and the node ring 13 are welded and fixed by overlapping the laser spots in the longitudinal direction of the joining portion. There is a method such as doing.

As a result of the experiment based on the above-mentioned embodiment, the number of experiments is n = 30. In the conventional example, the tensile strength is 8 to 10.
While it was 12 kg, it was confirmed that a tensile strength of 16 to 20 kg was obtained.

In this manner, the corresponding connecting portions 15 of the respective node rings 13 to which the four wire receivers 21 are attached at intervals of 90 degrees in the circumferential direction are rotatably connected by the rivets 16.

After that, the operation wires 18 are inserted into the four wire receivers 21 of the respective node rings 13 located at corresponding positions in the circumferential direction, and one end of the operation wire 18 is fixed to the node ring 13 located at the most distal end. It

In this embodiment, the cylindrical wire receiver 17 is used.
Since the wire receiver 21 manufactured by molding or shaving is used instead of using, the position of the operation wire insertion portion 23 can be arbitrarily changed at the time of manufacture so that the operation wire 18 can be set so as not to hit the rivet 16. Therefore, the operation wire 18 hits the rivet 16 and the insertability is deteriorated when the operation wire 18 is attached.
Insertion takes a long time, and after the operation wire 18 is attached, the operation wire 18 is bent by the rivets 16 and does not move smoothly, so that the turnability of each node ring deteriorates.
It is possible to eliminate the problem that the portion of the operation wire 18 that contacts the rivet 16 is rubbed.

Therefore, according to this embodiment, all the problems of the prior art can be eliminated.

[0035]

Second Embodiment FIGS. 6 to 8 show a second embodiment of the bending tube for an endoscope according to the present invention, FIG. 6 is a perspective view of a node ring having four wire receivers attached, and FIG. 7 is a perspective view of the wire receiver. FIG. 8 is an enlarged cross-sectional view of the portion to which the wire receiver is attached.

As shown in FIG. 6, the node ring 13 is provided with two long groove portions 19b and 19c corresponding to the fixed positions of both foot portions 32a and 32b of one wire receiver 31. The sizes of the long groove portions 19b and 19c are the wire receivers 31 described later.
The size is such that the legs 32a and 32b of the above can be fitted together. As shown in FIG. 7, the wire receiver 31 is formed of two foot portions 32a and 32b and an operation wire insertion portion 33 connecting the both foot portions.

Here, as in the first embodiment, the outer diameter is 8 mm,
The node ring 13 with a wall thickness of 0.3 mm is taken as a representative part. Wire receiver 31 connected to the node ring 13 of the above size
The thickness t ₁ of the feet 32a and 32b is 0.35 mm, the height k of the foot 32 is 0.5 mm, and the length L of the wire receiver 31 is L 1.
5 mm, the thickness t _{2 of} the operation wire insertion portion 33: 0.2 mm, and the size d of the inner peripheral surface of the operation wire insertion portion 33: φ 0.7 mm. Then, as shown in FIG.
The foot portions 32a and 32b of the wire receiver 31 are inserted into the long groove portions 19b and 19c provided in the node ring 13 up to the outer peripheral surface of the node ring 13, and the wire receiver 31 having a surface shape corresponding to the outer peripheral surface of the node ring 13 is formed. The legs 32a and 32b and the node ring 13 are welded and fixed by a laser beam or an energy beam such as an electron beam. For example, YA as an energy beam
When G laser light is used, it may be performed under the same conditions as in Example 1. Further, in the present embodiment, the leg portions 32a and 32b of the wire receiver 31 are connected to the long groove portions 19b and 19c of the node ring 13.
Since the penetration depth is not required as in Example 1, an output of 3 to 4 J is sufficient. Under the condition of the output of 3 to 4 J, the penetration depth q of 0.25 mm to 0.3 mm and the surface diameter p of the penetration part p: 0.55 to 0.6 mm can be obtained.

The laser beam irradiation method for melting and fixing the node ring 13 and the wire receiver 31 is the same as that in the first embodiment (for example, the method shown in FIGS. 4 and 5 is adopted). As for the result of the experiment based on, the tensile strength of 16 to 20 kg is obtained as in the first embodiment.

In this embodiment, as compared with the first embodiment, the wire receiver 31 can be welded with a smaller output, so that the running cost can be saved, and at the same time, the outer peripheral surface of the node ring 13 to which the laser or the like is irradiated is uneven. And burr can be prevented, post-processing such as deburring after welding is unnecessary, and the mounting position of the wire receiver 31 is regulated by providing the long groove portions 19b and 19c in the node ring 13, The mounting position of the wire receiver 31 will not be displaced, and the irradiation position of the laser light or the like can be clearly confirmed from the outer peripheral direction of the node ring 13, positioning will be easier, and the irradiation position of the laser light or the like will be displaced. There is a remarkable effect such as no.

[0040]

[Embodiment 3] FIGS. 9 to 11 show Embodiment 3 of the bending tube for an endoscope according to the present invention. FIG. 9 is a perspective view of a node ring having four wire receivers attached, and FIG. 10 is a perspective view of the wire receiver. FIG. 11 is an enlarged cross-sectional view of a portion to which a wire receiver is attached, and FIGS. 12 to 14 are explanatory views showing a laser light irradiation method.

Therefore, in this embodiment, the node ring 13 is provided with one groove portion 19 for one wire receiving and fixing position, as shown in FIG. The size of the groove portion 19 is such that the leg portions 42 of the wire receiver 41, which will be described later, can be fitted and assembled together. Figure 10
As shown in FIG.
2 is formed from the operation wire insertion portion 43 connected to 2.

Here, as in the first embodiment, the outer diameter is 8 mm,
The node ring 13 with a wall thickness of 0.3 mm is taken as a representative part. Wire receiver 41 connected to the node ring 13 of the above size
The thickness t _{1 of} the foot portion 42 is 1.2 mm, the height k of the foot portion 42 is k: 0.5 mm, the length L of the wire receiver 41 is 1.5 mm, and the thickness t ₂ of the operation wire insertion portion 43 is t _2. A component having a dimension of 0.2 mm and a size d of the inner peripheral surface of the operation wire insertion portion 43 of 0.7 mm is used. It is desirable that the thickness t ₁ of the foot portion 42 be equal to or longer than the outer circumference D (φ1.1 mm) of the operation wire insertion portion 43. Then, as shown in FIG. 11, the foot portion 42 of the wire receiver 41 is fitted into the groove portion 19 of the node ring 13 to irradiate the laser beam or the energy beam such as the electron beam from the outer peripheral surface side of the node ring 13. For example, when YAG laser light is used as the energy beam,
It suffices to carry out under the same conditions as in Example 2, 0.25 mm to 0.3
mm penetration depth q, penetration surface diameter p: 0.55-
It is possible to obtain 0.6 mm.

As a method of irradiating laser light for melting and fixing the node ring 13 and the foot portion 42 of the wire receiver 41,
As shown in FIGS. 12 and 13, the foot portion 4 of the wire receiver 41
The long side (length L) of 2 or the short side (thickness t ₁ ) is aimed at the contact point between the center and the node ring 13 and spot irradiation is performed, or as shown in FIG.
As shown in FIG.
A method such as overlapping the laser spots by aiming at the contact point with

In this embodiment, compared with the second embodiment, the node ring 13
Since there is only one groove to process, the processing time for the node ring 13 is short, and because there is only one fitting, the wire receiver 41 can be smoothly fed without requiring strict dimensional accuracy.
Has the effect of being able to be inserted into the node ring 13. Other functions and effects are similar to those of the first and second embodiments.

[0045]

[Embodiment 4] FIGS. 15 to 17 show Embodiment 4 of the bending tube for an endoscope according to the present invention. FIG. 15 is a perspective view of a node ring having four wire receivers attached, and FIG. 16 is a perspective view of the wire receiver. FIGS. 17A and 17B are enlarged cross-sectional views of the portion to which the wire receiver is attached.

As shown in FIG. 15, the node ring 13 is provided with one groove portion 19 at one wire receiving and fixing position. The size of the groove portion 19 is such a size that it can be combined with the leg portion 52 of the wire receiver 51 described later by fitting. As shown in FIG. 16, the wire receiver 51 includes the foot portion 5
2 and the operation wire insertion portion 53 connected to the foot portion 52 thereof.

Here, as in the first embodiment, the outer diameter is 8 mm,
The node ring 13 with a wall thickness of 0.3 mm is taken as a representative part. Wire receiver 51 connected to the node ring 13 of the above size
The thickness t _{1 of} the foot portion 52 is 0.4 mm, the height k of the foot portion 52 is 0.5 mm, the length L of the wire receiver 51 is 1.5 mm, and the wall thickness t ₂ of the operation wire insertion portion 53 is t _2. A component having a size of 0.2 mm and a size d of the inner peripheral surface of the operation wire insertion portion 53: φ0.7 mm is used. The thickness t ₁ of the foot portion 52 is larger than the wall thickness t ₂ of the operation wire insertion portion 53, and the wire insertion portion 5 has a maximum thickness t _2.
It is desirable that the wall thickness is as long as 3 of the thickness t ₂ . Then, as shown in FIG. 17, the foot portion 52 of the wire receiver 51 is fitted into the groove portion 19 of the node ring 13, and a laser beam or an energy beam such as an electron beam is emitted from the outer peripheral surface side of the node ring 13. For example, when YAG laser light is used as the energy beam, it may be performed under the same conditions as in Example 2, with a penetration depth q of 0.25 mm to 0.3 mm and a surface diameter p of the penetration part p: 0.55. It is possible to obtain 0.6 mm.

As a method of irradiating laser light for melting and fixing the node ring 13 and the foot portion 52 of the wire receiver 51,
12 to 14 in the third embodiment, and the results of the experiment based on the present embodiment are the same as those in the first embodiment.
Similarly, a tensile strength of 16 to 20 kg is obtained.

The present embodiment has an effect that a space inside the node ring 13 through which the fiber, the air / liquid feeding channel, and the forceps insertion channel are inserted can be made larger than that of the third embodiment. Other functions and effects are similar to those of the first to third embodiments.

[0050]

According to the present invention, when the wire receiver and the node ring are integrally welded by a laser or the like, the cross-sectional area where the boundary between the melted portion and the unmelted portion generated in the wire receiver is located. By using a wire receiver having a shape that is larger than the cross-sectional area of the operation wire insertion part of the wire receiver, the operation wire insertion part of the wire receiver, which is a thin part, is not affected by heat, and the wire receiver and node ring The welding strength with and is significantly improved. In addition, the operation wire does not hit the rivet that connects the node rings, so that the operation wire insertion property and the rotatability between the node rings are significantly improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a node ring according to a first embodiment.

FIG. 2 is a perspective view of a wire receiver according to a second embodiment.

FIG. 3 is an enlarged cross-sectional view of a portion to which a wire receiver of Example 3 is attached.

FIG. 4 is an explanatory diagram showing a laser light irradiation method of Example 1.

FIG. 5 is an explanatory diagram showing a laser light irradiation method of Example 1.

FIG. 6 is a perspective view of a node ring in which four wire receivers of Example 2 are attached.

FIG. 7 is a perspective view of a wire receiver according to a second embodiment.

FIG. 8 is an enlarged cross-sectional view of a portion to which a wire receiver of Example 2 is attached.

FIG. 9 is a perspective view of a node ring in which four wire receivers of Example 3 are attached.

FIG. 10 is a perspective view of a wire receiver according to a third embodiment.

FIG. 11 is an enlarged cross-sectional view of a portion to which a wire receiver of Example 3 is attached.

FIG. 12 is an explanatory diagram showing a laser light irradiation method according to a third embodiment.

FIG. 13 is an explanatory diagram showing a laser light irradiation method according to the third embodiment.

FIG. 14 is an explanatory diagram showing a laser light irradiation method according to a third embodiment.

FIG. 15 is a perspective view of a node ring in which four wire receivers of Example 4 are attached.

FIG. 16 is a perspective view of a wire receiver according to a fourth embodiment.

FIG. 17 is an enlarged cross-sectional view of the portion to which the wire receiver of Example 4 is attached.

FIG. 18 is a perspective view of a conventional flexible endoscope.

FIG. 19 is an enlarged sectional view of a conventional bending tube.

FIG. 20 is a perspective view of a node ring to which a conventional wire receiver is attached.

FIG. 21 is a perspective view of a node ring to which a conventional wire receiver is attached.

FIG. 22 is a perspective view of a node ring to which a conventional wire receiver is attached.

FIG. 23 is a cross-sectional view after laser irradiation showing a conventional example.

FIG. 24 is a cross-sectional view after laser irradiation showing a conventional example.

FIG. 25 is a sectional view after laser irradiation showing a conventional example.

FIG. 26 is an explanatory diagram of a defect in the conventional technique.

[Explanation of symbols]

1 flexible endoscope 2 operation part 3 Insert 4 Flexible tube 5 curved part 6 Tip component 7 Operation knob 8 Observation window 9 Eyepiece 10 universal code 11 operation buttons 12 Curved tube 13 joint rings 14 Short pipe section 15 Connection 16 rivets 17,21,31,41,51 Wire receiver 18 operation wire 19 groove 20 Operation wire insertion part 70 Melting part 71 Unmelted part 72 border

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Satoru Wakabayashi             Fukushima Prefecture Aizu-Wakamatsu City Kadota Town Large-scale Iiji Temple Muranishi             500 Olympus Optoelectronics Co., Ltd. Aizu Business             Inside the hall

Claims (2)

[Claims] 1. A bending tube having a wire receiver fixed to an inner surface of a node ring installed in a bending portion of an endoscope, when the wire receiver and the node ring are integrally welded by a laser or the like. A wire receiver having a shape in which a cross-sectional area where a boundary between a molten portion and an unmelted portion generated in the wire receiver is located is larger than a cross-sectional area of an operation wire insertion portion of the wire receiver is used. Curved tube for endoscope. 2. A bending tube formed by fixing a wire receiver to an inner surface of a node ring installed in a bending portion of an endoscope, wherein the operation wire insertion portion is located at a position where the operation wire does not hit a rivet connecting the node ring. 2. The bending tube for an endoscope according to claim 1, wherein the wire receiver provided with and the node ring are integrally welded.